Supercharged rice to feed the world

The discovery of C4 photosynthesis at a Brisbane sugar refinery 50 years ago spawned a whole new field of plant biology and is now well on the way to feeding the world.

Professors Bob Furbank and Susanne von Caemmerer are two of the scientists involved in creating ‘supercharged’ rice to feed the world. Credit: James Walsh, ANU

Three billion people rely on rice for survival, but C4 plants like maize and sugarcane grow faster, have higher yields, and are more drought-tolerant.

“C4 plants photosynthesise faster thanks to a biochemical ‘supercharger’ that concentrates CO2 in specialised structures in their leaves,” says Professor Bob Furbank from the ARC Centre of Excellence for Translational Photosynthesis.

“If we can modify rice to use the C4 pathway, instead of C3, we can improve rice production and double its water efficiency.”

In 2015, the first rice plant to contain the five genes necessary for C4 photosynthesis was created at the International Rice Research Institute in the Philippines.

The discovery of C4 photosynthesis by Hal Hatch and Roger Slack 50 years ago could soon help feed the world.

To speed up the evolution of rice from C3 to its C4 form, the researchers take genes from maize, splice them into the rice genome, then cross breed the rice until they get the combinations required to trigger the C4 pathway.

It’s a task that involves 12 institutions in eight countries, including Bob, who is a plant biologist, and his colleague Professor Susanne von Caemmerer, who has a background in mathematics.

Specialised cells (called bundle sheath cells) inside a C4 plant leaf (bottom) trap CO2 and allow it to photosynthesise more efficiently than a C3 plant like rice (top). Credit: International Rice Research Institute

“What I love about this project is that it has unified researchers from different fields for a common, and very worthy cause,” says Susanne.

“It’s also grabbed the attention of the Bill and Melinda Gates Foundation, who’ve just renewed our funding for the third time.”